Propulsion units, such as azimuth thrusters, are widely used in the maritime industry as primary or secondary means of propulsion for a broad range of vessel types.
Propulsion units are often provided with a propulsion unit nozzle arranged around the propeller and designed to increase the efficiency of the propulsion unit. The propulsion unit nozzle or propulsion unit nozzle affects the flow of water past the propeller and transfers hydrodynamic forces to the vessel. Propeller nozzles are used in connection with both pushing and pulling propulsion system.
Traditionally, propeller nozzles have been of a simple standardised design suitable for manufacturing as welted construction. However, with increased focus on efficiency and reduced emission, a need for propeller nozzles with improved hydrodynamic characteristics has arisen. Improved hydrodynamic characteristics may for example be achieved by designing propeller nozzles according to vessel and propulsion system characteristics and use. To be able to achieve such desirable hydrodynamic characteristics it is often necessary to design propeller nozzles with more complex surface geometries, such as surfaces of double and triple curvatures.
As traditional welding based manufacturing processes are not suitable for producing such surfaces of double and triple curvature, it would be advantageous with constructions that are easier and more effective in terms of design and manufacturing. Additionally, it would be advantageous to achieved improved manufacturing processes.